Telechronometer current converter



June 22 ,1926. 1,589,582v

l G. BABCOCK `TELECHRONOMETER CURRENT CONVERTER Filed Oct. 15, 1921 3 Sheets-Sheet 1 June 22 1926. 1,589,582

G. BABcocK TELECHRONOMETER CURRENT CONVERTER Filed Oct. l5, 1921 5 Sheets-Sheet 2 n l l l l l 67` u fa7-- FEI,

W55 65,' Qwz June 22 ,1926. 1,589,582

G.BABCOCK TELECHRONOMETER CURRENT CONVERTER Filed oct. 15, 1921 3 sheets-sheet s Gar/15071 BacUc/f Wma/Z/ Patented June 22, 1926.

UNITED STATES GARRISON BABCOCK, 0F EVERETT, WASHINGTON.

TELECHRONOMETELR, CURRENT CONVERTER.

Application filed October 15, 1921. Serial No. 508,038.

M y invention relates to means for convertmg, or securing reversals ot, current flow,

in electrical circuits and is concerned particularly with an improved converter, for securing current reversals in a telephone system employing a reversal responsive metering device and for applying them thereto,

especially that type ot' reversal responsive metering device, known under the tradename ot' telechronometei.

Whilemy present invention is particularly adapted for use in telephone systems, in which the service to the subscriber is metered through the application ot' current reversalsl to the meter, it is not limited to employment in telephone systems, or it employed in a telephone system, it is not limited to the spccitic telephone system, nor to the specific method ot connection and application which I have described in the following speciticatiou.

My present invention which is along the line ot the invention set out in my co-pending application, Serial No. 476,713, tiled .lune 1l, 1921, aims primarily toiprovide a simple, positive and inexpensive means vt'or securing reversals of current tlow suitable for actuating telechronometers on telephone lines and the like. Like my co-pending application, my present invention provides a resistance, or pair ot' resistances, for each direction ot current flow so connected that by reducing a resistance or pair of resistances, the potential to the meter will be reversed quickly but without producing' any abrupt change in current flow on the telephone system. My present invention provides an improved arrangement or alternately c0111-, pressing and releasing the resistances to shift the flow of lcurrent quickly and smpothly from one direction of flow to another; a balance indicator system having means for accurately and reliably indicating to the attendant any out ot balanced condition in the resistances and a. simple adjusting arrangement for quickly and positively adjusting the resistances to a balance. lVhere a pair ot' rcsistances are employed tor each direction ot current flow., this adjusting arrangement includes means for adjusting the sets ot' resirtances relative one another. and means for adjusting either resistance ot' either set relative the other. To assist in the proper adjustment o1 the various resistances, my present invention still further provides means whereby the attendant may readily apprise himself ot' the pertorn'iance, operation, or value ot any ol' the individual resistances employed.

Certain constructural features and arrangements of my present invention are novel and important, and these together with suoli other provisions as have not been hereinbeOre set forth will appear from the following detailed description taken with an inspection of the accompanying drawings in which:

Figure 1 is ay diagrammatic layout of a telephone system embodying my present invention;

Figure 2 is a front elevational view partly diagrammatic o'tl the rheostats and arrangement t'or operating the same; and

Figure 3 is a detached and simpliticd diagram ot' the pole changer circuit showing the arrangement for indicating any out ot b-alanced condition in the resistances.

As illustrated in Figure l, the system in connection with which l have illustrated a particular embodiment ot' my present invention, comprises the calling station A, called station B, and a. connecting circuit C, Iocated at a central switchboard.

At the subscriber-s station A and B, I llave illustrated in conjunction with the usual telephone apparatus, call registering devices 1 and 1 respectively adapted to be operated by reversals ot current. The particular meter or call registeringdevi'co illustrated is described in my co-pending application. Serial No. 508,037 tiled Oct. 15, 1921. Any other suitable metering device operating upon reversals of current, such as for example the meter described in my co-pending application, Serial No. 476,713, filed June 11, 1921 may be employed, as my present application relates more particularly to the manner ot' and 'means for securing the reversals of current.

The meter described in my above referred to applications are characterized by the use of two series coils connected in the two sides ot the talking line, and provided with suitable polarizing means and counter-actuating mechanism, whereby a complete cycle of the reversal of current is require-d for the actuation of the counting mechanism.

The calling station A comprises the usual transmitter 2, receiver 3, induction coil 4, hook switch 5, and ringer or call bell 6.

The station is connected to suitable terminals at central over the line wires 7 and 8, which line wires are provided with connections to a central battery 10, for supplying normal polarity of current over the line. The line is provided at central with a suitable answering jack 11, and multiple jacks, such as 12, connected through a suitable cut-oli relay 13, in a manner well known in the art. The line to station A is provided with a Suitable line signal 14, Jfor signaling or indicating to the operator at the exchange that a connection is desired. The signal 14 is controlled or governed by a line relay 15.

The connect-ing cord circuit C with which the central operator is provided, includes an answering plug 16 and a ringing plug 17, for cooperation with the line and multiple jacks, in making connections and inter-connections. The answering plug 16 is connected to the talking strands 18 and 19, and is provided with a third conductor 20 for controlling the actuation of the cut-off relay 13, and-the sleeve relay 21. A listening key 22 for placing the operators set 24 in communication with strands 18 and 19 is also' provided. At the ringing end of the cord' circuit, plug 17 is connected to talking strands 25 and 26, and is also connected to a third conductor 27, which serves to energize the line cut-olf relay 13 of the called line 7', 8 and the sleeve relay 28. The operator is provided with a ringing key 29, which'1`s adapted or connecting a ringing generator 30, or other source of ringing current to the conductors of the called line.

While I have illustrated a three-strand cord circuit in the particular embodiment of my present invention, which I have elected to describe, it is to be understood that the invention is not limited `in any manner to embodiment in a three-strand cord circuit and that my illustration of the same, as in the case of my co-pending application referred to hereinbefore, is for the purpose of clearly showing the invention in as simple a manner as possible. l

One end of cord circuit C is supplied with battery from the central source 10 over suitable connections which will be described later. These connections include the `answering supervisory relay 31, which, in connection with sleeve relay 21, controls the supervisory signal 32. In a similar manner, battery is fed to the rin ing end of the cord circuit from the centra source 10 over suitable connections, in this case wire 33, winding 34 and conductor 35 to the tip strand 25, and from the other side of the battery, over wire 36, winding 37 of the supervisory relay 38, conductor 39, to the ring or sleeve strand 26 of the ringing end of the cord circuit. The potential upon the ringing end of the cord circuit always remains in the same difi rection, due to the connections above de- Lsaeea scribed, so that no reversals of current upon the called line occurs, the calling line only being charged for the call.l

The pole changer device or current converter comprises two pairs of compression resistances R1, R2 and R3, R4 between which battery is connected over the conductors 45 and 46. The terminals 47 and 48 of the pole changer lead to the talking strands 18 and 19 respectively through the supervisory relay 31. The resistances shown are of the carbon piletype well known in the art. The resistances R1 and R2 are mechanically compressed together and the resistances R3 and R1 are actuated simultaneously by an arrangement which is one of the important aspects of my present invention, and will be described later.

One terminal of the battery 1() is connected with the lower ends of the resistances R1 and R3 by way of conductors 45, 50 and 45, v51 respectively. The upper end of the resist ance R1 is connected by way of a conductor 52 with terminal 48 of the pole changer. The upper end of the resistance R3 is connected by way of conductors 53 and 54 with the terminal 47. The lower ends of the resistances R2 and R2 are connected to they opposite terminal of the battery 10 by way of suitable conductors 55 and ,56 respectively. Obviously, if the resistances R1, R2 and R2, R4 are all equal there will be no difference of potential at the terminals 47 and 48. If the resistances R1, R2 are .simultaneously compressed to reduce the value of the same, the terminal 47 will exhibit a strong positive potential, while the terminal 48 will exhibit a' strong negative potential. ln other words, when the resistances R1L R2 are simultaneously compressed, a current flow will be set out through the talking strands as follows: from battery 10, through conductors 45 and 50, resistance R1 and out through the line by way of the conductor 52 and the terminal 48, back from the line through terminal 47, conductor 54, resistance R2 and to batter 10 by way of conductors 55 and 46.

f now, the ressure on resistances R1 and R2 is relaxe or released and simultaneously the pressure on resistances R3 and R2 is increased, the terminal 47 will exhibit a strong negative potential, while the terminal 48 will exhibit a strong positive potential- When the resistances R3 and R4 are simultaneously compressed, the current flow out through the talking stand is. as follows: conductors 45, 51, resistance R3, conductors 53 and 54 out through the line by way of terminal 47, and back through conductors 52 and 58, resistance R4 and conductors 56 and 46 to battery. The change from one potential t/o the other is performed without any interruption or abrupt change' in current ln order that the attendant may readily observe any out-of-balance conditions in the rheostats and easily adjust the same to a balance, I have incorporated a balance indicator 60 between the line feed and the battery.

It will now be apparent that when resistances R1, R2 are simultaneously compressed, a liow of current will be set up from battery 10, conductor 62 through the coil 61 of the indicator 60, which is now in parallel with resistance R1, out through the line by Way coil 61 is connected in a local circuit in Se' ries with R3 and the indicator coil 64 is connected in series with resistance R4. In the first instance, the voltage impressed upon the coil 61 is dependent upon the I R drop across R1, and the flow through the coil 64 is similarly dependent u on the I R drop across' resistance R2. In t ie second instance, the ow through the coils 61 and 64 will be dependent upon the respective values of the resistances R3 and R, which are connected in series with said coils 61 and 64, respec-v tively. In either case, any out-of-balancey condition will be indicated' so that it may be corrected in a manner which vwill hereinafter ap ear.

In ordier to clarify the operation of the pole changer, I have shown in Figure 3 a detached and simplified diagram of the connections showing the relation of the resistances in the circuitsf The battery 10 is connected to the common terminalv68 of the resistances R1 R3 and the common terminal 69 of the resistances R3, Rf. When the resistances R1, R2 are compressed and pressure on resistances R3, R4 relaxed currentiows vout through resistances R2 .b

way of terminal 47 over the line and bac by way of terminal 48 and through resistance R1 to battery. When the resistances R3 R* are'compressed Aand pressure on re-Y sistances R3, R2 relaxed current Hows-.out through resistance yR4 by way of terminal 48 over the lines and back by way of terminal 47 and through resistance R3, tobattery 10. Wheny thesupply is by way of the reslstances R1 R3, there will be a flow set up through the coils 61 and 64'inthe directions indicated Iby the arrows a and b respectively, while when the supply is by way of the resistances R3 R, the current iow set up in coils 61 and 64 will be in the same direction. Suitable pointers 72 indicate the respective'lows through the coils 61 `and 64 v and thereby the respective values of the uickly and convenientl the flow to and from the line is taking place.

The arrangement for actuating or compressing the pairs of resistances, which arrangement forms another important aspect of my present invention, comprises a pressure cylinder 73 for the rheostats R1, R2 and a pressure cylinder 74 for ythe rheostats R3, R4. Piston rods 75 and 76 connected at their inner ends to suitable pistons within the cylinders -7 3 and 74 respectively are adjustably connected at 77 and 78 with rheostat actuating shoes 79 and 80. Actuation of the respective rheostats is had by engagement of these actuating shoes with the 1nsulated buttons 81 thereof. The supply of compressed air or 'other suitable motive fluid-from the common intake conduit 82 tothe cylinders 73 and 74 is regulated by suitable adjustable pressure regulators or pressure reducing valves 83 and 84; conduit 82 may communicate with any suitable source of pressure. 87 provide exhaust outlets for discharging or exhausting the pressure from the chambers 73 and 74, while suitable valve memlbers 88 and 89v control the iiow to` an exposition. It will now be apparent that the actuation of one pair of reslstances or rheos'tats relative the other pair may be varied to suit the particular conditions in uestion Conduits 86 and by regulating the pressure admitte to the chambers 73 and 74 by means of the pressure regulators 83 and 84, while the degree of actuation of any resistance, relative the other resistance of the same set maybe l adjusted through t e connections 77 and 8.

The actuatin arms 92 and 93 for controlling the va ves 88 and 89 respectively are connected at their 'free ends to the opposite ends of a link 94, which link 94 is connected b'y a-pin joint at its center to the upperyend of actuating lever 95. A pair of bridging contact fingers 96 and 97 carried by the opposite end of the bar 95 .are adapted for bridging terminals 98, 99 and 100, 101 ofa valve controlling circuitr- The lever 95 is pivotally mounted centrally and is rigidly joined toa cross bar 102. The cross bar 102 is connected at its opposite ends through suitable links 103, 104 with the plungers or cores 105, 106 of a pair of solenoid windings 107, 108. The terminals llO lao

99 and 101 are grounded at 109 (Fig. 1).

The circuits through the solenoid windings 107 and 10S are controlled by a pair of time controlledrelays 110 and 111. The windings of the relays 1.10 and 111 are connected at one end to a battery 112 or other suitable source, which source is grounded as shown at 113. The circuits through the relays 110 and 111 are governed b v a time controlled circuit controller, which includes a cam wheel 117 mounted for example on the second shaft of a standard clock vand contacts 114 and 115 which are alternately closed by engagement of the cam portions of the wheel 1.17 therewith. These contact pins 114 and 115 are arranged at substantially 90O from eachother and the cam or wheel has two projections 190O apart so that the polarity is shifted every fteen seconds. Energization of the relay 110 actnates armature 11G to close the contacts 118 and thereby complete the circuit from battery 112 to solenoid winding 107 to ground 109 by Way of the tern'iinals 98 and 99 and linger 9G. assuming the contact finger 90 is in engagementwith the terminals 98 and 99.

Energization of the winding 107 causes movement of the plunger 105 inwardly, thereby swinging the bar 95 about its pivot to admit pressure to one of the cylinders for example 73, and exhaust the other 74, and thereby compress the resistances R1, R2 and release the pressure upon other pair R3, R4. This movement of the bar 95 moves the contact 96 out of engagement with the contacts 98 and 99 and the contact 97 into engagement with the contact pieces 100. and 101 selecting the circuit through the winding 1,08 which circuit is closed at the contacts 120 by engagement of the cam wheel 117 with' the contacts 115. Completion of the circuit through the winding 108 swings. the bar 95 in the opposite direction to compress the' other pair of resistances R3, It4 and selects the circuit through the winding 107. In this manner, a change from one direction of current flow to thecther is periodically effected in the calling line without any interruption or abrupt change.

To assist in the proper adjustment of the various resistances or rheostats, I provide an arrangement for indicating to the attendant the performance or operation of any of the individual rheostats. This includes a suitable voltmeter 125, a selecting switch 126 for connecting either of the resistances R1, R2, R3 or Rt individually thereacross and the necessary circuit connections therebetween.

I shall now describe briefly the operation of the particular system illustrated.v Assuming that subscriber A desires to be connected to subscriber B, the receiver 3 is raised, thereby completing a circuit from battery 10 as follows:

Battery 10, conductors 62, 130 and 131, line relay 15, line wire 8, through the instruments and meter at the station and back through line wire 7, conductors 132, 133, G0, and 40 to battery 10. Since the meter requires a complete cycle of current reversed it is not now actuated. Line relay 15 being thus energized closes a circuit from battery through line signal 14, indicating to the operator at the exchange that a connection is `medium of the listening key 22 communicates with the subscriber and receives the order for the desired connection, and assuming that the subscriber B is desired selects and tests the terminals of said line and proceeds to make the connection. The ringing key 29 is actuated to project ringing current over the called line, and when the party B answers. current flows in normal direction over the line of the called party, and conversation between the parties may be carried on.

The operation of the pole changer continues at all times. In the particular system illustrated, the calling party is charged for all'of the time consumed in making a connection and consummating the conversation. It is to be understood, however, that the charge may be for only the time during which the connection between the par-ties is established. This may be accomplished by cutting the terminals of the pole changer into the talking circuit of the calling line through the contacts of the supervisoryv answering relay 34 so that normal polarity of current prevails on the calling line until the called party responds. This is well known in the art and is, therefore7 not illustrated here.

The operation of the pole changer is as follows:

The time controlled wheel 117 rotates continuously, successively closingthe contacts 114 and 115 and thereby the circuits through the solenoid windings 107 and 108. The closing of these circuits is only momentary, suiicient to operate the valves 88 and 89 and set the connecting piece or bridge carried by the bar 95 for closing the other circuit. The operation of the valves 88 and S9 in turn controls release of one set of resistances and compression of the other set. A complete cycle of change of polarity occurring in the calling line from positive to negative and back to positive or vice versa causes an actuation or registration upon the meter 1 et the ceiling eeeeiee. If desired, the meter may be actuated by a reversal of current only i. e. from positive to negative or vice versa, but I prefer the use of a ferred to co-pending app meter which requires a complete cycle of alternation for registration of a count, such as the type set out in m hereinbefore reiication.

I do not intend to be Alimited to the particular embodiment shown and described.

The invention is not to be limited to telephone systems and the use of the compressible resistance in connection with the time controlled mechanism for operating the same is not to be limited to current reversal as mere variations `in current strength ma be employed in certain situations.

claim:

1. In combination, a air of carbon piles, fluid pressure means inc udin a single pressure cylinder and a piston, an means having adjustable connection with the piston for compressing both said piles by means of said piston, the adjustable connection between said last means and the piston permitting adjustment of the compression of one pile relative the other by means of said iston.

2. In combination, a pair of carbon piles, means for compressing said piles, and means for adjusting the compression of one of said piles with respect to the other by said compression means. e

3. In combination, a compressible resistance, fluid pressure means forY compressing said resistance to vary the same, valve means for governing the action of said fluid pres- `sure means, an electro-magnetic device, a circuit therefor, and means controlled by said `-electro-magnetic device forA operating said valve means and simultaneously Iinterrupting said circuit. independently of said fluid pressure means.

4. In combination, a variable resistance, means for varyin said resistance, electromagnetic means or operating said resistance varying means, and a circuit therefor, said resistance var ing means being operated and said circuit' interrupted automatically by the operation of said electro-magnetic means and independently of said resistance varyirig'means.

5. In combination, a pairof variable resstances, a member for varying said resistances jointly, and an actuating member for said first member, said actuating member having adjustable connection with said lirst member to ermit varying the relative joint variation ci) said resistances, said adjustable connection comprising'y a member pivfoted to one of said first members and slidably adjustable upon the other of said members.

6. In combination, a pair of carbon piles, a shoey for compressing said carbon piles, a shoe actuating member, and an adjustable connection between the shoe actuatin member and said shoe, said means comprising a member pivoted to the actuating member and slidably adjustable-upon the shoe.

7. In combination, a pair of variable resi stances, a shoe for varying said resistances, a fluid pressure chamber, a piston operable in said chamber, and a mechanical connection between said piston and said shoe.

8. In combination, a pair of variable resistances, an actuating member for varying said resistances, a fluid pressure chamber, and a piston operable in said chamber, said piston having adjustable mechanical connection with the actuating member between said resistances.

9. In combination, two pairs of adjustable resistances, a member for varying the two resistances of one pair, a member 'for varying the two resistances ofii the other pair, fluid pressure means for actuating said members, valve means for adjusting the relative variations between the two pairs of resistances and mechanical means for adjusting the relative variations between the two resistances of each pair.

10. In combination, two pairs of adjustable resistances, a member for varying the two resistances of one pair, a member for varying the two resistances of the other pair, a pair of uid pressure chambers, pistons operable one in each of said chambers and one having connection with each of said resistance varying members, a fluid supply conduit for said chambers, valved connections from said conduit to said chambers, means for automatically operating said valved connections alternately and separate controlling means for said connections.

11. In combination, a pair of resistances, a pair of fluid pressure devices for varying said resistances, and means for regulating said pressure devices to control the relative variations effected in said resistances thereby. 12. In combination, two pairs of carbon piles, a shoe for compressing one of said pairs of carbon piles, a shoe for compressing the other of said pairs of carbon piles, a pair of fluid pressure operated pistons, a shoe actuating member subject to the pressure of one of said pistons, said member having. ad-

justable connection withone of said comhaving a uni-directional circuit in circuit with both said pairs of resistances to indicate any out of balance condition in either of said pairs of resistances.

14. In combination, a lVheatstone bridge circuit having two pairs of resistances in its arms, a source of' current connected across said bridge, and a balance indicator having a pair of coils connected in parallel with the resistanccs of one pair of said resistances, and series connections between said indicator coils and the other pair of resistances. r

l5. In combination, a pair of resistances, a second pair of rcsistan'ces, means for alternately causing a flow of current through said tivo pairs of resistances, and a common balance indicator' for indicating any out of balance in the resistances of both said pairs.

16. In combination, a potentiometer circuit, comprising two variable resistances, terminals connected to said potentiometer circuit, fluid pressure means for varying said resistances alternately, and time controlled means governing said fluid pressure means.

17. In a telephone system, a talking line,

means for supplying current periodically in reverse directions oversaid line, said means comprising a potentiometer circuit including a pair of non-interruptible variable resistances, a pair of fluid pressure operated pistons for alternately varying said resistances, a time controlled circuit controller for controlling said pistons and indicating means for determining the variation of said resistances.

18. In combination, a pole changer comprising a pair of non-interruptible 'variable rheostats, a pair of fluid pressure operated pistons for changing the resistances of said rheostats alternately, electro-magnetic means for controlling said pistons and a time controlled circuit for said electro-n'iagnctic lIlQllS.

19. In a pole changer, a pair of noninterrnptible rheostats, movable means for alternately varying the resistance of said rheostats, a pair of fluid pressure operated pistons, electro-magnetic means for controlling said pistons and time controlled l means for ,controlling of said' electro-inagnetic means.

Q0, In combination, a pair of non-inter'- ruptible rheostats for changing the polarity of an electrical circuit, a voltmeter and means for connecting either of the rheostats separately across said voltmeter to indicate the resistance of the respective rheostats.

21. ln combination, a lllheatstone bridge circuitI having compressible resistanees connected in the arms thereof, said resistances being mechanically grouped intivo opposite nairs, fluid pressure operated means' for compressing said pairs of resistances alternately and means for indicating a condition of electrical imbalance separately between the tivo resistances of each pair,

22. In combination, a compressible resistance, a fluid operated piston, valve means governing the action of said piston, means forY controlling said valve means, and time controlled means governing the action of 24. In combination, a compressible resistance, a circuit having a counting device responsive to compression of said resistance, a fluid operated piston for compressing sai resistance, valve means governing the actuation of said piston, a magnet? for actuating said valve, a time controlled contact device governing the energization of said magnet.

25. In combination, a compression rheostat, a fluid operated piston, a cylinder, a fluid connection therefor, a pressure regulating valve governing the pressure applied to the piston, a valve for admitting and eX- hausting fluid pressure to and from the cylinder, means for controlling said last valve, and time controlled means governing the action of said valve controlling means.

26. In combination, a compression rheostat, a fluid operated piston, a cylinder, a fluid connection therefor, a pressure regulating valve governing the-pressure applied to the piston, a valve for admitting and eX- hausting fluid pressure to and from the cylinder, means for controlling said last valve, time controlled means governing the action of said valve controlling means, and mea-ns for indicating the relative electrical resistance of said rheostat.

27. In combination, a pair of compression rheostats, a common operating piston for compressing said rheostats, a cylinder therefor, an adjustable mechanical connection between said piston and said rheostats for distributing the pressure between said rheostats, and electrical indicatin means for indicating the relative electrica resistances of said rheostats. 28. In combination, a potentiometer circuit comprising tvvo variable resistances, terminals connected to said potentiometer circuit, fluid pressure means for varying said resistances alternately, and automatic means for governing the action of said fluid pressure means.

29. In a telephone system, a talking line, means for supplying talking current periodically in reverse directions over said line, said means comprising a potentiometer battery supply circuit including a pair of noninterrnptible variable resistances, pain of fluid pressure operated pistons for alter- Cil nately varying said resistances, an auto` matic circuit controller for controlling the application of pressure to said pistons, and indicating means for determining the variation of said resistances.

30. In combination, a pole changer comprising a pair of non-interruptilole variable rheostats, a pair of fluid pressure operated pistons for changingtlie resistanees of said rheostats alternately, and electro-magnetic means for automatically controlling the pistons to actuate said resistances periodically.

3l. In a pole changer, a pair of noninterruptilole rheostats, movable means for alter- 15 nately varying the resistance of said rheostats, a pair of fluid pressure operated pistons, electro-magnetic means for controlling said pistons, anda rotating shaft forcentrolling the electromagnetic means to actuate the rheostats periodically.

32. In combination, a compressible resistance, a iuid operated piston, valve means governing the action of said piston, a circuit having electromagnetic means for controlling the valve governing means, contacts for the circuit and a constantly moving cam for actuating said contacts.

In. Witness whereof, I hereunto subscribe my name this 6th day of Getober 1921.

GARRISON BABCOCK. 

